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Water Essentials: Optimizing Water Quality for Steamers and Combi-ovens

Introduction Today’s combi-ovens and steamers promise versatile, efficient, predictable results at the push of a button. At the core of their performance is steam. Steam is 100% Water - Chemical characteristics of water can have a significant impact on equipment and are often the cause of costly repairs and shortened equipment life. It is impossible to enjoy the benefits of cooking with steam without careful consideration of water quality. Properly applied, water treatment will reduce scale and corrosion problems, assure efficient equipment operation, and eliminate expensive service calls and downtime.

It is an investment in the success and profitability of your business. Service interruptions, costly repairs and operating inefficiencies can be far more expensive than guarding against them. Water treatment insures that your equipment is producing when you need it most. Water chemistry and the physics involved with different methods of generating steam can be complex. Most oven manufacturers have stringent water quality standards that must be adhered to. The key is in applying the right water treatment technology appropriate for addressing the various contaminants. The purpose of this guide is to help you make the best decision about water treatment for your unique application.

Five Types of Contaminants & How to Deal With Them

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There is a lot in water that can cause added wear on parts. Fine silt, dirt, rust and other debris provide a catalyst for scale build-up. Filtration technologies work like a ‘net’ to trap and hold objects larger than the holes in the net. The smaller the holes, the more fine particulates are removed.

All OptiPure systems filter out suspended particulate matter down to 0.5 micron in size. To get an idea how small this is, a human hair is about 90 microns thick. That’s a complex net! The media structure of the OptiPure cartridge is entirely composed of fibers coated with powdered activated carbon (PAC), making it ideal for removing chlorine. To put that in perspective, one pea sized ball of PAC is equivalent to half a football field in surface area. A dense structure of these carbon coated fibers, built on a core, make up the entire depth of the CTO and CTOS cartridges used in OptiPure systems. OptiPure’s activated carbon chlorine reduction media contributes to the exceptional NSF Certified performance and capacity of OptiPure systems.

Particulates (dirt, sediment, rust)

Chlorine (taste & odor) While the disinfectant Chlorine is used to make our water safe to drink, it contributes to corrosion in steam equipment and gives an offensive taste and odor which can affect steam quality. Activated carbon is the best technology for taking out disinfectant chlorine.

Hardness (scale or lime-scale) A common and expensive water related problem with steam equipment is the formation and accumulation of scale. Varying amounts of scale-forming compounds (primarily calcium and magnesium in the form of carbonates) are present in water supplies. These dissolved ‘hardness’ minerals become concentrated in boilers and steam generators due to evaporation. Concentration and heat force them out of solution where they form as hard, adherent, rock-like deposits. Scale deposits on heat transfer surfaces act as an insulating layer which prevents the efficient transfer of heat. OptiPure ScaleX2 systems are ideal for reducing scale with ovens that use a boiler or steam generator.

f With boilerless “flash- type” steam generation all of the dissolved solids are rapidly forced out of solution and form deposits on the heating elements, blower wheel and on surfaces within the oven. Over time scale build-up impedes steam production, reduces energy efficiency, increases maintenance requirements and eventually causes equipment shut-down requiring expensive service.

Total Dissolved Solids Water is nature’s solvent. It contains everything it can dissolve on the way to your tap. TDS (Total Dissolved Solids) is the measure of a broad array of chemical contaminants (primarily minerals) dissolved in water. TDS includes chlorides, sulfate, iron, silica and sodium to name a few. The scale- forming ions of calcium and magnesium carbonate are also dissolved solids, but testing is necessary to determine how much of the TDS is made up of hardness minerals. When present, chlorides can also be problematic with steam equipment.

Reverse osmosis removes a broad range of minerals (>97% of TDS) from water. Ion exchange “softening” systems will only remove select ions, specifically the ones that contribute to hardness or alkalinity, but have little or no impact on TDS and do not remove unwanted TDS, such as chlorides, sulfates or silica.

If your goal is to avoid equipment problems associated with high TDS and meet manufacturer water quality parameters, OptiPure OP or BWS is the right choice.

This enables you to establish and maintain a “Water Quality Standard” regardless of variations in water supplies at different locations; and to avoid seasonal changes in water quality common with many water supplies.

OptiPure BWS and OP Series systems use reverse osmosis to remove TDS. These systems include features that allow the user to manage the TDS level and the mineral content of the treated water.

Chlorides (corrosion) Corrosion is the deterioration of materials due to reactions within the environment. Chloride is a compound that becomes particularly reactive at higher temperatures (140-212o F) and can penetrate the passive film on stainless steel allowing a corrosive attack to occur. Chlorides can be corrosive to stainless steel even at low levels. Corrosion can be rapid, destructive and expensive with steam equipment; drastically reducing equipment life. OP (Mineral Addition) and BWS (blended water system) reduce chlorides from water significantly reducing the potential for corrosion with all types of steam equipment. At low levels IsoNet® helps protect against chloride corrosion, especially with boilers and steam generators.

OptiPure OP and BWS Systems include a range of Optimized water storage tanks with variable-flow re-pressurization systems to assure consistent equipment operation at all times.

Important Things To Know About Your Equipment and Your Water

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How Does the Oven Generate Steam?

Different methods of making steam can require different types of water treatment. You must understand how an oven generates steam in order to select the right water treatment system. What matters most is whether the oven contains a volume of water that is ‘boiled’ to generate steam or whether it takes in water that is instantly ‘flashed’ into steam.

Boiler – A volume of water is contained and heated to generate steam. This includes ovens with boilers, steam generators and ovens with open reservoirs of water inside the oven cabinet. Most ovens with a boiler or steam generator have a ‘blow-down’, ‘drain’ or ‘drain & flush’ feature. Flash – Water is dispensed onto a heated surface and instantly ‘flashed’ into steam. This method involves some type of mechanism for dispensing water directly onto a heated surface or element that is hot enough to rapidly vaporize, or “flash” the water into steam. Minerals, dissolved in the water, are forced out of solution in the flash steam process and deposit in the oven.

s You can find our recommendations for each of these types of steam equipment in the equipment section located in Chapter 3 of this guide.

Basic Characteristics of Water

Total Dissolved Solids (TDS) - all of the inorganic and organic substances in water that are present in their molecular or ionized form (ppm or mg/l). Dissolved ions make up the majority of TDS and is what enables electricity to pass through water. Water Hardness (as CaCO3) – a measure of scale-forming compounds of calcium and magnesium. Hardness can be expressed in ppm (parts per million) or mg/l (milligrams per liter). It can also be expressed as Grains per Gallon (GPG). Chloride – Chlorides are soluble, active ions that can trigger a corrosive attack in steam equipment. Chloride (Cl-) levels are also expressed in ppm or mg/l.

Alkalinity – is the capability of water to neutralize acid. As it pertains to equipment, alkalinity is an indicator of the potential or tendency for hardness minerals to form scale. Low alkalinity can indicate potential for corrosion. pH- a measure of the relative balance between acid and alkaline substances in water. It is an indicator of whether water has a tendency to be scale-forming, or corrosive. Silica – is a very hard mineral found in quartz and opal, and is a common constituent of sand. Small amounts of silica can form a very hard scale that is difficult to remove. Silica is expressed in ppm or mg/l.

Learn About the Water Quality At Your Location

OptiPure offers customized water analysis that provides in-depth information. However water chemistry can have significant chemical variations seasonally, or even daily due to the use of different water sources or blending patterns. It is important to understand these variables when deciding the right water treatment for your application. Alternatively, water utilities are required to provide an annual water quality report that often includes needed water quality information and the high/low range of contaminant variations throughout the year.

Why do you need a water analysis?

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Optimize Your Water for Steam Equipment

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Introduction There are two fundamental ways to deal with Water Hardness and TDS: 1.   Inhibit problems with minerals Inhibiting technologies do not remove minerals but rather discourage the formation of scale. 2.   Remove problematic minerals Removal technologies take out dissolved minerals that cause scale and contribute to corrosion. These technologies significantly reduce problems by removing problematic minerals.

OptiPure OP and BWS systems utilize reverse osmosis and are designed to allow an operator to manage their water quality to meet manufacturer’s standards, maximize operating efficiency and protect their investment.

Addressing water also helps to maintain the requirements of the warranty on your equipment. Is it reasonable to require these standards be met to validate warranties? Yes – Optimized water quality can drastically reduce water-related problems and support or promotes years of consistent, trouble-free performance from your combi oven or steamer.

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Optimized Water Standards For Warranty Requirements

‘Optimized’ Water* (based on warranty requirements from major manufacturers of combi ovens & steamers)

Hardness 30 – 120 ppm (2 – 7 grains)

TDS 30 – 120 ppm

Silica 12ppm or less

Chloride 30 ppm or less

Free Chlorine Less than 0.1 ppm

pH 7.0 to 9.0

Most water in North America will not meet these standards without treatment. Total dissolved solids, hardness and chloride levels can be 5 or even 10 times higher than this. *These parameters are general and include the primary contaminants listed by oven manufacturers. Many variables can influence the overall impact water will have on equipment in a given application. Please contact OptiPure for additional recommendations or solutions.

Identify the potential water-related problem in your situation and it’s impact on your business

•  How frequently will your equipment require service, and at what cost?

•  Are water-related problems covered under the equipment warranty?

•  How will downtime & service interruption affect business?

•  How does scale build-up affect equipment operating efficiency?

•  How can corrosion impact equipment life and what is the replacement cost?

The bottom line is: if you don’t understand what filtration does, and how it can impact your business, it’s tough to make the best choice. Our goal is to help you understand how water contaminants can affect your business and the best treatment options available. The following recommendations are based upon our systems’ tested and proven ability to protect equipment against undesirable water characteristics.

Reverse Osmosis (RO) – Unlike filtration, this technology purifies water by forcing it under pressure through a membrane while flushing contaminants away to drain. RO is a near absolute removal process that takes out virtually all TDS. This degree of purity can promote corrosion and other complications with equipment. Optimized water for steam equipment must have a balance of minerals that minimizes scale and guards against corrosion. OptiPure OP and BWS systems include features that allow the user to manage the TDS level and the mineral content of the treated water. “Optimized Water” water quality is maintained despite geographical/seasonal variations in water characteristics.

OptiPure OP and BWS Series Reverse Osmosis Systems

Consider When •  Water Quality does not

meet manufacturer requirements.

•  Maximum protection against water-related problems is desired.

(Removal Technology)

OP and BWS Systems reduce a broad range (typically >97%) of TDS and other contaminants. 4

Boiler & Flash Steam ü  Recommended for:

A range of systems offer different production rates and storage tank options to meet any equipment requirements. Each system includes complete pre-treatment, RO processor, TDS blending or mineral addition, digital water quality monitor and storage tank with re-pressurization.

ScaleX2® protects steam equipment against scale by inhibiting the formation of calcium carbonate hardness. ScaleX2® instantly transforms dissolved calcium carbonate hardness minerals into microscopic particles through the process of “template assisted crystallization”. The particles, suspended in solution, can no longer form hardness compounds and are flushed away when the boiler or steam generator is drained during automatic or routine ‘drain and flush’ procedures. The ScaleX2® systems also reduce chlorine and provide nominal sediment reduction down to 0.5 micron (NSF).

ScaleX2 Consider When

•  Water quality does not meet manufacturer requirements.

•  Low to high level of calcium carbonate hardness.

•  pH is less than 8.6

(Inhibiting Technology)

ScaleX2® is recommended with steam equipment that utilizes boilers and steam generators; and boilerless combi’s with steam reservoirs inside the cook cabinet. To maximize the scale inhibiting benefits of ScaleX2 it is important that the boiler or steam generator is drained or blown-down on a daily basis.

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Boiler Steam ü  Recommended for:

IsoNet®, is a patented scale inhibitor and corrosion protection technology. IsoNet® interferes with the formation of hardness compounds which inhibits the formation and accumulation of scale. What makes IsoNet® unique is its patented design that allows for consistent delivery of media and greater capacity. The IsoNet® media also provides a protective barrier on metal surfaces to help guard against corrosion. OptiPure systems with IsoNet® also reduce chlorine and provide nominal sediment reduction down to 0.5 micron (NSF).

IsoNet® Consider When

•  Water quality does not meet manufacturer requirements.

•  Low to moderate hardness and TDS levels.

(Inhibiting Technology)

IsoNet® ensures consistent dosing by trapping and holding the right blend of scale & corrosion inhibitor media in the ideal position within the core of the cartridge. Inhibitor media dissolves into the water stream where it reacts with dissolved minerals and interferes with the formation of hardness compounds. IsoNet® also helps protect surfaces against corrosion.

Boiler & Flash Steam ü  Recommended for:

Selecting the Right System Once you choose the right water treatment technology for your application, you must select a system that will meet your usage requirements. A properly sized water treatment system will assure that your equipment always performs at its peak. To select the right system it is important to calculate the amount of water your equipment will use; especially with an OP or BWS system. Consider the following: CONNECTION – Does your equipment have a separate water connection for steam and for condensate water? If is does, (this is common) calculate how much water you will need to generate steam during a typical day (gal./hr x hrs/day). Calculate and add other uses of ‘treated’ water, such as oven cleaning. This will vary depending on the manufacturer. Never connect the filtered/treated water to the condensate water connection.

If it does not (this is not common), calculate all daily water usage including the amount of condensate water that goes to the drain. CAPACITY – As a general rule, a filter system (IsoNet/ScaleX2) ‘rated capacity’ should meet or exceed the actual water usage of the equipment for the period between filter changes. In the case of OP or BWS RO systems the daily production rating needs to exceed the daily water needed by the oven allowing for temperature and pressure fluctuations. FLOW RATE – The filter systems or re-pressurization system ‘flow rate’ should be greater than the peak flow requirement of the equipment it serves. Contact the equipment manufacturer or OptiPure for assistance with calculating water usage requirements and selecting the right system.

Don’t Forget the Filter

Perhaps the most important and most overlooked component of realizing the benefits of water treatment is replacing filter cartridges on a routine basis. Properly applied and maintained, water treatment will yield tremendous benefits to a foodservice operation. The benefits are proven and the value is measurable. But your business will not benefit from even the best water treatment if filter cartridges are not replaced on a timely basis. In most applications OptiPure filtration systems perform for six month to one year between filter changes.

Check the system specification sheets for detailed filter change information. The catalog and system spec sheets are available online at www.optipurewater.com

B Contact your OptiPure Distributor or OptiPure for assistance with scheduling your routine filter replacements.